Hi, Not clear how you want your output in matrix: Try this: dat1<-structure(list(Env = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 3L, 3L, 3L, 3L, 3L, 3L, 3L), .Label = c("23", "55", "67", "Env"), class = "factor"), place = structure(c(7L, 7L, 7L, 2L, 1L, 11L, 11L, 11L, 11L, 5L, 6L, 6L, 3L, 8L, 2L, 1L, 4L, 4L, 10L, 10L, 10L), .Label = c("Ck", "CK", "Dk", "IN", "jk", "NO", "NW", "PK", "place", "PR", "PT"), class = "factor")), .Names = c("Env", "place"), row.names = 2:22, class = "data.frame")
dat1[]<-sapply(dat1,as.character) list1<-lapply(lapply(split(dat1,dat1$place),`[`,1),table) mat1<-matrix(unlist(list1),ncol=3) names(mat1)<-names(unlist(list1)) mat1 # [,1] [,2] [,3] #[1,] 1 1 3 #[2,] 1 2 1 #[3,] 1 1 3 #[4,] 1 2 4 #attr(,"names") #[1] "Ck.23" "Ck.67" "CK.23" "CK.67" "Dk.55" "IN.67" "jk.23" "NO.23" "NW.23" #[10] "PK.55" "PR.67" "PT.23" mat1["Ck.23"] #Ck.23 # 1 mat1[mat1==3] #NW.23 PR.67 # 3 3 Hope this helps. A.K. ----- Original Message ----- From: Nico Met <nicome...@gmail.com> To: R help <r-help@r-project.org> Cc: Sent: Monday, October 8, 2012 8:42 AM Subject: [R] How to count combinations Dear all, Need a help. I would like to count combination of two columns: structure(list(V1 = structure(c(4L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 3L, 3L, 3L, 3L, 3L, 3L, 3L), .Label = c("23", "55", "67", "Env"), class = "factor"), V2 = structure(c(9L, 7L, 7L, 7L, 2L, 1L, 11L, 11L, 11L, 11L, 5L, 6L, 6L, 3L, 8L, 2L, 1L, 4L, 4L, 10L, 10L, 10L), .Label = c("Ck", "CK", "Dk", "IN", "jk", "NO", "NW", "PK", "place", "PR", "PT"), class = "factor")), .Names = c("V1", "V2"), class = "data.frame", row.names = c(NA, 22L)) For example: how many times 23 appear with NW and then I want to put the out put as a matrix NW Ck PT jK NO DK PK IN PR 23 3 55 67 Many thanks in advance Nico [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.